BUREAU OF RECLAMATION DENVER LIBRARY 92098804 9 20 9 88 0 4 MISCELLANEOUS PAPER H-69-1 c- TRENDS IN BAFFLED, HYDRAULIC JUMP STILLING BASIN DESIGNS OF THE CORPS OF ENGINEERS SINCE 1947 by D. R. Basco I * □ID 1 0! January 1969 Sponsored by Assistant Secretary of the Army (R6-D) * Department of the Army Conducted by U. S. Army Engineer Waterways Experiment Station CORPS OF ENGINEERS Vicksburg, Mississippi ARMY-MRC VICK8BURO. MISS. THIS DOCUMENT HAS BEEN APPROVED FOR PUBLIC RELEASE AND SALE; ITS DISTRIBUTION IS UNLIMITED w FOREWORD » This report grew out of the need for a general, experimental study of drag coefficients for baffle blocks in hydraulic jump type spillway energy dissipators. Sponsored by the U. S. Army Engineer Waterways Experi­ ment Station (WES) (In-House Laboratory Independent Research), the general study wiil be published in a lati r WES technical report. This survey of the trends of Corps designs has provided the investigator with greater perspective when viewing the Corps of Engineers work with that of other investigations throughout the world. The report was prepared by David R. Basco, Research Hydraulic Engineer, Locks Section, Structures Branch, of the Hydraulics Division. Colonel Levi A. Brown, CE, was director of the Waterways Experiment Station during the preparation. Mr. E. P. Fortson, Jr., was Chief of the Hydraulics Division. ♦ 1X1 manm CONTENTS Page FOREWORD ....... iii NOTATION ...... vii SUMMARY. .......... v Introduction . , . 1 Limitations. 1 Tabulated Results. 1 $ 2 Analysis of Results. 2 General........ 2 Tailwater Depths 11 i Basin Length' . 16 .1 Baffle Blocks. 17 General . Location. 17 Height. 18 Width . 20 Spacing . 20 20 Distance between Rows. ....... 23 • End Sill ............ 25 Comparison with Current WES Design Criteria. 25 Conclusions....................... 29 REFERENCES to '»'■•WiMWJigiJ" ».'w.w u p m 1 li t . NOTATION Maximum spillway discharge, cfs Width of rectangular stilling basin, ft Maximum unit discharge, cfs/ft Average velocity at inlet section to hydraulic jump, ft/sec Average inlet depth, ft Inlet Froude number Average depth of tailwater immediately downstream of forced hydraulic jump,ft Sequent or conjugate depth of free hydraulic jump, ft Critical open channel flow depth, ft Downstream depth when jump begins to sweep-out of the basin, ft Length of the stilling basin, ft Location of the baffle blocks (first row) on the stilling basin floor, ft Vertical height of the baffle block, ft Horizontal width of the baffle block, ft Horizontal spacing between baffle blocks in a particular row, ft Horizontal distance between front faces of two rows of baffle blocks, ft Vertical height of end sill, ft. Horsepower SUMMARY This report summarizes the last twenty-one years of Corps of Engineer hydraulic model tests on spillways with hydraulic jump type energy dissipators using baffle blocks and end sills. From the averages, maximums and minimums, general trends, and other information presented it is hoped that the reader will obtain a general picture of Corps of Engineer designs. No attempt was made to completely compare the results with those of other hydraulic laboratories. TRENDS IN BAFFLED, HYDRAULIC JUMP, STILLING BASIN DESIGNS OF THE CORPS OF ENGINEERS SINCE 1947 Introduction ♦ 1. It is often important in any evolutionary design process to review previous designs in order to gain clearer insight into future trends. Surveys of this type are also necessary to place the designs of one organization in proper perspective with those of similar U. S. organizations and also with those throughout the world. 2. The object of this report, therefore, is to summarize the last twenty- one years of hydraulic model tests on spillways with hydraulic jump type energy dissipators using baffle blocks and end sills. From the averages, maximums and minimums, general trends, and other information presented it is hoped that the reader will obtain a general picture of Corps of Engineer designs. No attempt was made to completely compare the results with those of other hydraulic laboratories. Limitations 3. The study was limited to baffled, approximately rectangular, stilling basins that were used below high, concrete and earth dam spillways where the hydraulic jumps formed are either free or only slightly submerged. Low head spillways that are often connected with navigation dams usually have highly submerged jumps. Because of the physical difference in these jumps,.' this group lends itself to an independent study. Similarly, outlet works stilling basins were not included because of the three-dimensional affects of the diverging channel walls. Also, the large run-of-river projects model w - iv ’ mum*. ... * it I I * iI jtested at the Bonneville Hydraulic Laboratory were kept separate from those ! I 1 tested at .the Waterways Experiment Station. i 4. The currently revised "List of Publications" of the U. S. Army Engineer Waterways Experiment Station^- was used as the source for available Technical « i Reports. Any omissions were unintentional. The twenty-two projects model 1 tested at the Waterways Experiment Station (WES) with Technical Reports dating from 1947 were of primary interest. Tabulated Results 5. The complete tabulation of all primary and computed information is shown as Table 1. The nomenclature used in Table 1 is defined in Fig. 1 and under Notation, p.vii. Many of the similar dimensionless ratios were included because of their appearance in the literature and because none alone has gained widespread use. 6. Each column in Table 1 is c.onsectively numbered and because of its size and complexity Table 2 has been prepared to simplify explanation. The values shown in Table 1 for baffle block and end sill geometry were those chosen for the final design and represent the ultimate engineering compromise between hydraulic performance and economics. « 7. Where applicable, Table 1 also lists the maximum, minimum and mean values. Average values are greatly distorted by extremes and therefore must be observed with caution. They do, however, give some idea of the magnitude and geometry of a typical project. Analysis of Results 8. General . Some indication of the prototype size of the projects tested . * 9 i , *¡¡> , ' smw TABLE 1 - TABULATED RESULTS 1 i MAX. SASIN A/AX. 1 7»/¿|se?. ¿»a? ¥ MAX. /2!¿¿ MAX. b a v h ce/r ÍAS/V <u /VÖ. | OUT D a m TW FLOOR w tw m r Wid t h UNIT 4 ^ oW LEU. $3 te s fíe //W S0T« dso d m Is a n BLEY. EL£V. to ELEV. 0 W % c(/ / 5 c/tw n ( d a t e ) d 2 de d o d z <7t 7-ss d i TW f t 1 ÍS f t f t f t c fs f t $MC f t -ft ■H f t H / 2. 3 4 S C» 7 8 9 10 // n /3 /4 ¡ 5 ( 7 m P 2 0 W 22 Z3 WBS / TOCKS ISLAND (&) 445.0 3 4 4 .0 701.0 211.5 452,000 3 7 0 \22Z 96.6 (1.1 4.6 72.5 80.0 35.9 0.^0 60. S 0.76 5-7 204.0 2.5 w 2 COPAN (69) 140.5 7 /0 . © 29.7 ' 6/* 4.0 139,670 224 8 9 3 6 3 5 (4.0 3.0 46.0 53.2 29 Z Ö.SC?40.6 0.77 3.3 115.5 2 2 45 3 815 W5S7* PO//Vr(68) 646.8 6 0 5 .0 4 Í 8 5 4 5 .0 422,000 3 5 0 1205 70.0 tro 3.0 60.0 63.0 35,6 550 0.81 a s 8S.^ (.2^ 50 4 80S KAYSJMG2R (éel 75 Ti 676. S 74.3 61 2.0 284,000 180 1580 93-01 (%.0 3.4 í4 £ 81.0 42.6 oso a 4 210.0 2 .6 l_52l 5 7/9 SHELBY//¿LE(&>) 639.2 575. e 62.4 51 3.0 162,500 (5 6 1048 74-7 13.5 3.6 51.0 62.8 32 5 0-9( 54.0 o.so 4.2 I2S.O 2 0 76 é 665 STOCKTON (05) 904.8 800-0 104.0 738.0 174,000 184 950 950 lo.O 5.3 62.0 73.0 3 0 .5 0.85 5¿.o o.76 6 2 225 0 3. ( 56 7 673 SED ROCK (65) 19 7 3 7 /7 -2 74./ 6 5 4 0 362,600 241 . 1.295 92 3 (8.2 3 .4 63.2 /8.7 37.4 0.30 C2.0 0-77 3.5 206.5 2.6 50 8 655 ,4^/5 7740 (64) i i 45 .2 967.5 /7 Ö 2 8 7 5 O ¡ 545,000 950 1626 /28.0 (2.8 6.3 92.5 1070 43.5 o.% 910 0.E5 7 2 2343 22 ! 53 5 645 PROCTER (64) /2D/.5 . 7 6 9 . 6 32.5 1 1 2 2 0 432,000 5 2 0 831 63.0 (3.0 3.1 470 5¡.0 27.8 0.82 43.0 0-8 5 3.6 /56-0 3.0 45 (O 62 / Allegheny (¿3) / 370.0 i 2 3 0 .0 740.0 m s .o (40.0CC 2 0 4 6 8 7 10 4 .0 6.7 7.0 5/0 63.0 Z4.5 0-81 48.0 0-76 7-0 178.3 28 52 // 6// REDMOND (Oí) /0 7 4 .5 1 0 4 2 .5 32.0 í0 0 0 .0 577,000 6.4.4 870 61.0 //.O 3.2 42.5 48.0 251 0.89 3.9 141.0 2.9 : 16 /z 605 Sí ó BEND (EZ) i 4 2 3 0 /3 79.0 44.0 (32 o.o 390,000 31 (> (0 3 6 7 1 .0 14.5 3.3 590 61.0 312 0.?7 54.0 0.89 4 ./ 194.0 3.2 14 U) t3 575 EUPAULA (41) (,0 4 7 51677 S3.0 4 ¿0 .0 4c0,000 510 8 8 5 89 0 (0.0 4P) 56 7 670 29.0 o.g5 53o 0.77 5.7 168 0 2.5_ S3 ¡4- 568 CAZLYLE (Cl) 4¿¿._9 A á 4 ,S _ _22.4_ AOQ.O 160,000 179 8 9 3 5 4 0 (6.0 2.4 44.5 47.0 29.2 0-95 47.0 0.8? 2.8 (42.0 So 45" 15 555 KEYSTOUE (¿0) '?&*>.